In my previous post I mentioned some odd results that led me to additional analyses. Below is a screen snapshot summarizing one such analysis, of the ordered associations between mortality in the 35-69 and 70-79 age ranges and all of the other variables in the dataset. As I said before, this is a subset of the China Study II dataset, which does not include all of the variables for which data was collected. The associations shown below were generated by HealthCorrelator for Excel.

The top associations are positive and with mortality in the other range (the “M006 …” and “M005 …” variables). This is to be expected if ecological fallacy is not a big problem in terms of conclusions drawn from this dataset. In other words, the same things cause mortality to go up in the two age ranges, uniformly across counties. This is reassuring from a quantitative analysis perspective.

The second highest association in both age ranges is with the variable “SexM1F2”. This variable is a “dummy” variable coded as 1 for male sex and 2 for female, which I added to the dataset myself – it did not exist in the original dataset. The association in both age ranges is negative, meaning that being female is protective. They reflect in part the role of gender on mortality, more specifically the biological aspects of being female, since we have seen before in previous analyses that being female is generally health-protective.

I was able to add a gender-related variable to the model because the data was originally provided for each county separately for males and females, as well as through “totals” that were calculated by aggregating data from both males and females. So I essentially de-aggregated the data by using data from males and females separately, in which case the totals were not used (otherwise I would have artificially reduced the variance in all variables, also possibly adding uniformity where it did not belong). Using data from males and females separately is the reverse of the aggregation process that can lead to ecological fallacy problems.

Anyway, the associations with the variable “SexM1F2” got me thinking about a possibility. What if females consumed significantly less wheat flour and more animal protein in this dataset? This could be one of the reasons behind these strong associations between being female and living longer. So I built a more complex WarpPLS model than the one in my previous post, and ran a linear multivariate analysis on it. The results are shown below.

What do these results suggest? They suggest no strong associations between gender and wheat flour or animal protein consumption. That is, when you look at county averages, men and women consumed about the same amounts of wheat flour and animal protein. Also, the results suggest that animal protein is protective and wheat flour is detrimental, in terms of longevity, regardless of gender. The associations between animal protein and wheat flour are essentially the same as the ones in my previous post. The beta coefficients are a bit lower, but some P values improved (i.e., decreased); the latter most likely due to better resample set stability after including the gender-related variable.

Most importantly, there is a very strong protective effect associated with being female, and this effect is independent of what the participants ate.

Now, if you are a man, don’t rush to take hormones to become a woman with the goal of living longer just yet. This advice is not only due to the likely health problems related to becoming a transgender person; it is also due to a little problem with these associations. The problem is that the protective effect suggested by the coefficients of association between gender and mortality seems too strong to be due to men "being women with a few design flaws".

There is a mysterious factor X somewhere in there, and it is not gender per se. We need to find a better candidate.

One interesting thing to point out here is that the above model has good explanatory power in regards to mortality. I'd say unusually good explanatory power given that people die for a variety of reasons, and here we have a model explaining a lot of that variation. The model explains 45 percent of the variance in mortality in the 35-69 age range, and 28 percent of the variance in the 70-79 age range.

In other words, the model above explains nearly half of the variance in mortality in the 35-69 age range. It could form the basis of a doctoral dissertation in nutrition or epidemiology with important implications for public health policy in China. But first the factor X must be identified, and it must be somehow related to gender.

Friday, October 28, 2011

Musique et SanteThe wonderful Musique et Sante who regularly work with our collegues at the Royal Northern College of Music, (RNCM) have developed their own website, which I recommend to you all. Partners and allies of the finest quality.http://www.musique-sante.org/en

Bi-Monthly Networking Evening (a change to our advertised programme)I'll be 'out of service' for much of November, and instead of cancelling the networking evening planned for the end of the month, I'm thrilled that Holly at the RNCM has offered network members the opportunity to attend a talk on Music for Health as part of the RNCM Research Forum Series. It will take place on Wednesday 23 November at 5.15pm – 6.45pm in the RNCM Lecture Theatre and is entitled ‘Creating musical space in a medical place’. Holly Marland will be sharing insights into the role that music can play in hospital settings and the training and support that can be offered to musicians. There will be an opportunity for discussion and some informal networking in the RNCM bar afterwards. Places are limited so if you’d like to come along, please drop holly an email at holly.marland@rncm.ac.uk

Greater Manchester Arts Health Network LibraryI am thrilled to be supporting the Greater Manchester Arts Health Network website which was formally opened last week. This on-line resource provides a fantastic one-stop-shop for some of the latest thinking, research and development in the field. Please check it out and in particular the extensive LIBRARY.Fantastic work Anne and Phil.http://www.greatermanchesterartshealth.org.uk/

Brief thoughts on the Un-ConferenceLast Thursday’s Un-Conference was a (long) day of challenging, exciting and provocative debate and activity around our arts/health field. Divided into 4 themed sessions, the day gave the opportunity to participants to engage in 1 or more of the day’s events.

Langley Brown and Phil Burgess were quick to provoke and excite, getting people on their feet and active and using deeply personal stories of their own experiences as artists to question narratives and in part suggest, that its never too late to have a happy childhood.

Lynn Frogett and her team shared their psychosocial approach to understanding how the arts can change individuals and communities through theory and practice in an interactive workshop exploring how practitioners and organisations can evidence this.

Clive, Dorothy and Anne

Dorothy Rowe was utterly compelling and shared some of her thoughts on the myth of depression and its chemical origins, alongside notions of imagination. The repose to Dorothy’s session has been quite overwhelming. Thought Provoking Inspiring Moving and concise

Mark O’Neil and Leisa Gray gave an excellent two-hander to round the day off, exploring the potential of museums and galleries to impact on public health at a population level, and a more intimate hands-on experience of literally handling objects. A perfect end to a wonderful day.

A Gentle Prod at those who take for granted...The venue wasn’t perfect for the day, with some distracting noise from people working, and a couple of people complained there wasn’t food! I do have some sympathy about the ambient distractions, but for those demanding food…the day was free to all participants, and cost a fortune to host. So, no more greedy bleating please.

The graph below shows the results of a multivariate linear WarpPLS analysis including the following variables: Wheat (wheat flour consumption in g/d), Aprot (animal protein consumption in g/d), Mor35_69 (number of deaths per 1,000 people in the 35-69 age range), and Mor70_79 (number of deaths per 1,000 people in the 70-79 age range).

Just a technical comment here, regarding the possibility of ecological fallacy. I am not going to get into this in any depth now, but let me say that the patterns in the data suggest that, with the possible exception of some variables (e.g., blood glucose, gender; the latter will get us going in the next few posts), ecological fallacy due to county aggregation is not a big problem. The threat of ecological fallacy exists, here and in many other datasets, but it is generally overstated (often by those whose previous findings are contradicted by aggregated results).

I have not included plant protein consumption in the analysis because plant protein consumption is very strongly and positively associated with wheat flour consumption. The reason is simple. Almost all of the plant protein consumed by the participants in this study was probably gluten, from wheat products. Fruits and vegetables have very small amounts of protein. Keeping that in mind, what the graph above tells us is that:

- Wheat flour consumption is significantly and negatively associated with animal protein consumption. This is probably due to those eating more wheat products tending to consume less animal protein.

- Wheat flour consumption is positively associated with mortality in the 35-69 age range. The P value (P=0.06) is just shy of the 5 percent (i.e., P=0.05) that most researchers would consider to be the threshold for statistical significance. More consumption of wheat in a county, more deaths in this age range.

- Wheat flour consumption is significantly and positively associated with mortality in the 70-79 age range. More consumption of wheat in a county, more deaths in this age range.

- Animal protein consumption is not significantly associated with mortality in the 35-69 age range.

- Animal protein consumption is significantly and negatively associated with mortality in the 70-79 age range. More consumption of animal protein in a county, fewer deaths in this age range.

Let me tell you, from my past experience analyzing health data (as well as other types of data, from different fields), that these coefficients of association do not suggest super-strong associations. Actually this is also indicated by the R-squared coefficients, which vary from 3 to 7 percent. These are the variances explained by the model on the variables above the R-squared coefficients. They are low, which means that the model has weak explanatory power.

R-squared coefficients of 20 percent and above would be more promising. I hate to disappoint hardcore carnivores and the fans of the “wheat is murder” theory, but these coefficients of association and variance explained are probably way less than what we would expect to see if animal protein was humanity's salvation and wheat its demise.

Moreover, the lack of association between animal protein consumption and mortality in the 35-69 age range is a bit strange, given that there is an association suggestive of a protective effect in the 70-79 age range.

Of course death happens for all kinds of reasons, not only what we eat. Still, let us take a look at some other graphs involving these foodstuffs to see if we can form a better picture of what is going on here. Below is a graph showing mortality at the two age ranges for different levels of animal protein consumption. The results are organized in quintiles.

As you can see, the participants in this study consumed relatively little animal protein. The lowest mortality in the 70-79 age range, arguably the range of higher vulnerability, was for the 28 to 35 g/d quintile of consumption. That was the highest consumption quintile. About a quarter to a third of 1 lb/d of beef, and less of seafood (in general), would give you that much animal protein.

Keep in mind that the unit of analysis here is the county, and that these results are based on county averages. I wish I had access to data on individual participants! Still I stand by my comment earlier on ecological fallacy. Don't worry too much about it just yet.

Clearly the above results and graphs contradict claims that animal protein consumption makes people die earlier, and go somewhat against the notion that animal protein consumption causes things that make people die earlier, such as cancer. But they do so in a messy way - that spike in mortality in the 70-79 age range for 21-28 g/d of animal protein is a bit strange.

Below is a graph showing mortality at the two age ranges (i.e., 35-69 and 70-79) for different levels of wheat flour consumption. Again, the results are shown in quintiles.

Without a doubt the participants in this study consumed a lot of wheat flour. The lowest mortality in the 70-79 age range, which is the range of higher vulnerability, was for the 300 to 450 g/d quintile of wheat flour consumption. The high end of this range is about 1 lb/d of wheat flour! How many slices of bread would this be equivalent to? I don’t know, but my guess is that it would be many.

Well, this is not exactly the smoking gun linking wheat with early death, a connection that has been reaching near mythical proportions on the Internetz lately. Overall, the linear trend seems to be one of decreased longevity associated with wheat flour consumption, as suggested by the WarpPLS results, but the relationship between these two variables is messy and somewhat weak. It is not even clearly nonlinear, at least in terms of the ubiquitous J-curve relationship.

Frankly, there is something odd about these results.

This oddity led to me to explore, using HealthCorrelator for Excel, all ordered associations between mortality in the 35-69 and 70-79 age ranges and all of the other variables in the dataset. That in turn led me to a more complex WarpPLS analysis, which I’ll talk about in my next post, which is still being written.

I can tell you right now that there will be more oddities there, which will eventually take us to what I refer to as the mysterious factor X. Ah, by the way, that factor X is not gender - but gender leads us to it.

Monday, October 17, 2011

Perfect Health Diet is a book that one should own. It is not the type of book that you can get from your local library and just do a quick read over (and, maybe, write a review about it). If you do that, you will probably miss several important ideas that form the foundation of this book, which is a deep foundation.

The book is titled “Perfect Health Diet”, not “The Perfect Health Diet”. If you think that this is a mistake, consider that the most successful social networking web site of all time started as “The Facebook”, and then changed to simply “Facebook”; which was perceived later as a major improvement.

Moreover, “Perfect Health Diet” makes for a cool and not at all inappropriate acronym – “PHD”.

What people eat has an enormous influence on their lives, and also on the lives of those around them. Nutrition is clearly one of the most important topics in the modern world - it is the source of much happiness and suffering for entire populations. If Albert Einstein and Marie Curie were alive today, they would probably be interested in nutrition, as they were about important topics of their time that were outside their main disciplines and research areas (e.g., the consequences of war, and future war deterrence).

Nutrition attracts the interest of many bright people today. Those who are not professional nutrition researchers often fund their own research, spending hours and hours of their own time studying the literature and even experimenting on themselves. Several of them decide to think deeply and carefully about it. A few, like Paul Jaminet and Shou-Ching Jaminet, decide to write about it, and all of us benefit from their effort.

The Jaminets have PhDs (not copies of their books, degrees). Their main PhD disciplines are somewhat similar to Einstein’s and Curie’s; which is an interesting coincidence. What the Jaminets have written about nutrition is probably analogous, in broad terms, to what Einstein and Curie would have written about nutrition if they were alive today. They would have written about a “unified field theory” of nutrition, informed by chemistry.

To put it simply, the main idea behind this book is to find the “sweet spot” for each major macronutrient (e.g., protein and fat) and micronutrient (e.g., vitamins and minerals) that is important for humans. The sweet spot is the area indicated on the graph below. This is my own simplified interpretation of the authors' more complex graphs on marginal benefits from nutrients.

The book provides detailed information about each of the major nutrients that are important to humans, what their “sweet spot” levels are, and how to obtain them. In this respect the book is very thorough, and also very clear, including plenty of good arguments and empirical research results to back up the recommendations. But this book is much more than that.

Why do I refer to this book as proposing a “unified field theory” of nutrition? The reason is that this book clearly aims at unifying all of the current state of the art knowledge about nutrition, departing from a few fundamental ideas.

One of those fundamental ideas is that a good diet would provide nutrients in the same ratio as those provided by our own tissues when we “cannibalize” them – i.e., when we fast. Another is that human breast milk is a good basis for the estimation of the ratios of macronutrients a human adult would need for optimal health.

And here is where the depth and brilliance with which the authors address these issues can lead to misunderstandings.

For example, when our body “cannibalizes” itself (e.g., at the 16-h mark of a water fast), there is no digestion going on. And, as the authors point out, what you eat, in terms of nutrients, is often not what you get after digestion. It may surprise many to know that a diet rich in vegetables is actually a high fat diet (if you are surprised, you should read the book). One needs to keep these things in mind to understand that not all dietary macronutrient ratios will lead to the same ratios of nutrients after digestion, and that the dietary equivalent of “cannibalizing” oneself is not a beef-only diet.

Another example relates to the issue of human breast milk. Many seem to have misunderstood the authors as implying that the macronutrient ratios in human breast milk are optimal for adult humans. The authors say nothing of the kind. What they do is to use human breast milk as a basis for their estimation of what an adult human should get, based on a few reasonable assumptions. One of the assumptions is that a human adult’s brain consumes proportionally much less sugar than an infant’s.

Yet another example is the idea of “safe starches”, which many seem to have taken as a recommendation that diabetics should eat lots of white rice and potato. The authors have never said such a thing in the book; not even close. "Safe starches", like white rice and sweet potatoes (as well as white potatoes), are presented in the book as good sources of carbohydrates that are also generally free from harmful plant toxins. And they are, if consumed after cooking.

By the way, I have a colleague who has type 2 diabetes and can eat meat with white potatoes without experiencing hyperglycemia, as long as the amount of potato is very small and is eaten after a few bites of meat.

Do I disagree with some of the things that the authors say? Sure I do, but not in a way that would lead to significantly different dietary recommendations. And, who knows, maybe I am wrong.

For example, the authors seem to think that dietary advanced glycation end-products (AGEs) can be a problem for humans, and therefore recommend that you avoid cooking meat at high temperatures (no barbecuing, for example). I have not found any convincing evidence that this is true in healthy people, but following the authors’ advice will not hurt you at all. And if your digestive tract is compromised to the point that undigested food particles are entering your bloodstream, then maybe you should avoid dietary sources of AGEs.

Also, I think that humans tend to adapt to different macronutrient ratios in more fundamental ways than the authors seem to believe they can. These adaptations are long-term ones, and are better understood based on the notion of compensatory adaptation. For instance, a very low carbohydrate diet may bring about some problems in the short term, but long-term adaptations may reverse those problems, without a change in the diet.

The authors should be careful about small errors that may give a bad impression to some experts, and open them up to undue criticism; as experts tend to be very picky and frequently generalize based on small errors. Here is one. The authors seem to imply that eating coconut oil will help feed colon cells, which indeed seem to feed on short-chain fats; not exactly the medium-chain fats abundantly found in coconut oil, but okay. (This may be the main reason why indigestible fiber contributes to colon health, by being converted by bacteria to short-chain fats.) The main problem with the authors' implied claim is that coconut oil, as a fat, will be absorbed in the small intestine, and thus will not reach colon cells in any significant amounts.

Finally, I don’t think that increased animal protein consumption causes decreased longevity; an idea that the authors seem to lean toward. One reason is that seafood consumption is almost universally associated with increased longevity, even when it is heavily consumed, and seafood in general has a very high protein-to-fat ratio (much higher than beef). The connection between high animal protein consumption and decreased longevity suggested by many studies, some of which are cited in the book, is unlikely to be due to the protein itself, in my opinion. That connection is more likely to be due to some patterns that may be associated in certain populations with animal protein consumption (e.g., refined wheat and industrial seed oils consumption).

Thankfully, controversial issues and small errors can be easily addressed online. The authors maintain a popular blog, and they do so in such a way that the blog is truly an extension of the book. This blog is one of my favorites. Perhaps we will see some of the above issues addressed in the blog.

All in all, this seems like a bargain to me. For about 25 bucks (less than that, if you trade in quid; and more, if you do in Yuan), and with some self-determination, you may save thousands of dollars in medical bills. More importantly, you may change your life, and those of the ones around you, for the better.

Ai Weiwei tops the art world’s ‘power 100 list’…whatever that is!‘His art activism has been a reminder of how art can reach out to a bigger audience and connect with the real world…Institutions, while they are really important, can be great tombs.’Mark Rappolt, Editer, Art Review

How we value older people, the arts and the 'market'I’m thrilled to be giving the opening key-note at the 3rd Annual Art of Good Health and Wellbeing International Arts and Health Conference, which is taking place at the National Gallery of Australia, Canberra between the 14 and 17 November 2011. I’ve written a paper which explores the role of the arts when we are faced with serious illness and which asks, in the face of our own mortality, just what relevance can culture and the arts play, if any. An article in today’s Gurdian chimes with much of the sentiment of my paper (see directly below)

The Hon Simon Crean MP Minister for Regional Australia, Regional Development and Local Government, Minister for the Arts, will be opening the conference and I’ll be giving my paper at around 6:15 on Monday the 14th, so if you want to hear it and get involved in our international debate, please come along.http://www.artsandhealth.org

Illustration by Andrzej Krauze

﻿ NHS end-of-life care has been crippled by a marketised mindset that sees everything in terms of its economic value'Our market-shaped way of life has no time for the elderly or the art of caring.' Madeline Bunting captures some of the outrageous issues affecting us all, around how we age; end of life care and the insidious ‘market led’ approach to ‘care.’http://www.guardian.co.uk/commentisfree/2011/oct/16/market-no-time-elderly-caring

What young people are really thinking?The Art of Protest is a pop-up exhibition organised that will take place in empty shops on Manchester's Market Street from 19 to 27 October. The charity Noise sent photographers Liam Carter, Sebastian

Heise, Lucia Zapata and Marta Julve out on the streets of Manchester, Madrid, Valencia and Berlin, to ask young people the question: 'What would make you protest?' Displaying the resultant images in an area hit by the recent riots is a powerful statement of disillusioned youth

On the Secular Beatification of St Perry of EssexI’m often asked if I’m after a ‘celebrity’ to be a patron of Arts for Health, and in truth, we’ve had some great people behind our work over the years including Lord Attenborough; Joan Bakewell; Melvyn Bragg and Sam Taylor-Wood, but the current obsession with fame and all its glories, has left a bit of doubt in my mind around publicity, for publicity’s sake. Much of this has been reflected by the vapid self-celebration of contemporary British art.

This said, I had an almost revelatory moment at the British Museum this weekend, in the exhibition by Grayson Perry: Tomb of the Unknown Craftsman, which I would recommend to anyone, particularly the people who ask, ‘what’s the relationship between arts and heath?’ I tend to open up a conversation about it being more than just a prescription...

Perry has produced something completely exquisite in his curation of artifacts’ from the British Museum and creation of his own work. I don’t particularly think he lays it on with a trowel either. It’s a beautiful show, with some challenging work that whilst exploring Perry’s own experience of being human, offers though the arts, far wider thoughts on being individual and part of a community. It’s not dumbed down in the slightest…if anything, he ups the ante.﻿

An artists answer to the credit crisis…Michael Landy’s Credit Card Destroying Machine was unveiled at the Frieze Art Fair last week. The huge Jean Tinguely-inspired contraption, pieced together from a random collection of found objects such as mannequin limbs and Mickey Mouse figures, is surrounded by tiny bits of shredded credit cards on the floor. In return for a drawing made by the machine that bears Landy’s signature, people have to hand over a valid credit card for shredding. An assistant feeds pre-signed sheets of paper into the machine and off it goes, with a marker pen attached to a metal arm doing an automated random drawing (you can choose the colour). Some 300 credit cards were shredded during the first day alone (including the private view). Landy, of course, is best known for shredding all his worldly possessions a few years ago. (Thanks to itsnicethat.com and Thomas Dane)http://www.itsnicethat.com/articles/michael-landy-frieze-2011http://www.thomasdane.com/artist.php?artist_id=7

...and for all of you eagerly awaiting Part 1 of the m a n i f e s t o for arts/health, I can confirm that the wonderful Kamila Kasperowicz has been creating a stunning digital and hard copy version for your delectation…

Monday, October 10, 2011

The International Federation of Arts Councils and Culture Agencies (IFACCA) has announced that Chile would host the 6th World Summit on Arts and Culture in its capital, Santiago, on 13-16 January 2014.

This will be the first time that the World Summit has been staged in Latin America and will be presented in Santiago’s award-winning Estación Mapocho Cultural Centre. One of IFACCA’s most significant initiatives, the World Summit on Arts and Culture provides national arts councils, ministries of culture and other agencies with an opportunity to discuss key issues affecting public support for the arts and creativity. Previous World Summits on Arts and Culture has been held in Canada (2000), Singapore (2003), England (2006), South Africa (2009) and Australia (2011).

Provisionally entitled Creative Citizens: Technology and Culture for Diversity, the theme for the 6th World Summit will address the current context of globalisation and the challenges in the cultural arena, specifically in relation to safeguarding and protecting cultural diversity and cultural identities. New technologies in culture represent an opportunity to impact positively on the visibility and legitimatisation of cultural identities, to foster increased cultural diversity, and to enhance access, production and exchange of cultural goods.At the General Assembly, IFACCA also launched WorldCP, an international database of cultural policies [http://www.worldcp.org].For further information please see www.ifacca.org

Camila Vallejo on a march in Santiago held on the anniversary of the Pinochet coup that toppled President Salvador Allende in 1973. Photograph: Aliosha Marquez/AP

Chile...Girls Demand Free University Education

‘It was the most beautiful moment, all of us in school uniform climbing over the fence, taking back control of our school. It was such an emotional moment, we all wanted to cry.’ Angelica Alvarez 14

With the IFACCA announcement freshly ringing in our ears, its worth noting how a group of teenage girls kick started what is known in Chile as the ‘Chilean Winter’. There’s not been much in the UK press on this story, with our focus facing towards the ‘Arab Spring’, but here’s a synopsis.

A group of young girls have occupied Carmela Carvajal primary and secondary school for five months fighting for a single goal: free university education for all. The girls took a vote on their action too, with a 10/1 in favour of action, and their days are organised through a democartic voting system for managing all aspects of their lives, but their argument is simple; that education is recognised as a common right for all, not a consumer good to be sold on the open market.

This is part of a vast student uprising across Chile, with weekly protest marches gathering between 50,000 and 100,000 students. The girls are still having a rich education, supplemented by yoga and salsa and music gigs. There’s an excellent article on this story by Jonathan Franklin at:

So, with a World Summit on Arts and Culture and a democratic Student Uprising, lets hope that the IFACCA board see it in their remit to explore how culture and the arts are a force for social change, and if a core part of their agenda is about Creative Citizens and Technology, then this is potentially an exciting and provocative summit and one where our ever-evolving arts/health/well-being agenda is central.

And whilst use of facebook and twitter is being used as evidence of dissent in the UK resulting in lengthy prison sentences for those who advocate civil dissobedience, in Chile we can see how creative citizens have in fact harnessed this technolgy. Here are two links to the student leader, Camila Vallejo Dowling's blog and twitter...http://twitter.com/#!/camila_vallejohttp://www.camilapresidenta.blogspot.com/

Anyone Who Has a Heart is a light sculpture that displays your heart rate. It is a landmark and signature artwork sited at the entrance to the new Royal Manchester Children’s Hospital. The sculpture aims to catch attention through its form, textures and movement. giving a sense of fun and playfulness for all ages. Walking around the sculpture triggers sensors and changes the light display. Holding onto the stainless steel hand grips monitors your heart rate and translates that into a red light display synchronised with your pulse. It can also tell you the time as every hour, the sculpture turns into a clock. The sequence is explained on floor panels along with information about the heart rate of a range of animals.

It was commissioned by Lime in collaboration with the Central Manchester University Hospitals NHS Foundation Trust. This stunning work was made by artist Andrew Small commissioned through a special arts programme allocation from the hospital’s Charitable Funds.

Costly traits have evolved in many species (e.g., the male peacock’s train) because they maximize reproductive success, even though they are survival handicaps. Many of these traits have evolved through nature’s great venture capitalist – sexual selection.

(Source: Vangoghart.org)

Certain harmful mental disorders in humans, such as schizophrenia and manic–depression, are often seen as puzzles from an evolutionary perspective. The heritability of those mental disorders and their frequency in the population at various levels of severity suggests that they may have been evolved through selection, yet they often significantly decrease the survival prospects of those afflicted by them (Keller & Miller, 2006; Nesse & Williams, 1994).

The question often asked is why have they evolved at all? Should not they have been eliminated, instead of maintained, by selective forces? It seems that the most straightforward explanation for the existence of certain mental disorders is that they have co-evolved as costs of attractive mental traits. Not all mental disorders, however, can be explained in this way.

The telltale signs of a mental disorder that is likely to be a cost associated with a trait used in mate choice are: (a) many of the individuals afflicted are also found to have an attractive mental trait; and (b) the mental trait in question is comparatively more attractive than other mental traits that have no apparent survival costs associated with them.

The broad category of mental disorders generally referred to as schizophrenia is a good candidate in this respect because: - Its incidence in human males is significantly correlated with creative intelligence, the type of intelligence generally displayed by successful artists, which is an attractive mental trait (Miller & Tal, 2007; Nettle, 2006b). - Creative intelligence is considered to be one of the most attractive mental traits in human males, to the point of females at the peak of their fertility cycles finding creative but poor males significantly more attractive than uncreative but wealthy ones (Haselton & Miller, 2006).

The same generally applies to manic–depression, and a few other related mental disorders.

By the way, creative intelligence is also strongly associated with openness, one of the "big five" personality traits. And, both creative intelligence and mental disorders are seen in men and women. This is so even though it is most likely that selection pressure for creative intelligence was primarily exerted by ancestral women on men, not ancestral men on women.

Crespi (2006), in a response to a thorough and provocative argument by Keller & Miller (2006) regarding the evolutionary bases of mental disorders, makes a point that is similar to the one made above (see, also, Nettle, 2006), and also notes that schizophrenia has a less debilitating effect on human females than males.

Ancestral human females, due to their preference for males showing high levels of creative intelligence, might have also selected a co-evolved cost that affects not only males but also the females themselves though gene correlation between the sexes (Gillespie, 2004; Maynard Smith, 1998).

There is another reason why ancestral women might have possessed certain traits that they selected for in ancestral men. Like anything that involves intelligence in humans, the sex applying selection pressure (i.e., female) must be just as intelligent as (if not more than) the sex to which selection pressure is applied (i.e., males). Peahens do not have to have big and brightly colored trains to select male peacocks that have them. That is not so with anything that involves intelligence (in any of its many forms, like creative and interpersonal intelligence), because intelligence must be recognized through communication and behavior, which itself requires intelligence.

Other traits that differentiate females from males may account for differences in the actual survival cost of schizophrenia in females and males. For example, males show a greater propensity toward risk-taking than females (Buss, 1999; Miller, 2000), and schizophrenia may positively moderate the negative relationship between risk-taking propensity and survival success.

Why were some of our ancestors in the Stone Age artists, creating elaborate cave paintings, sculptures, and other art forms? Maybe because a combination of genetic mutations and environmental factors made it a sexy thing to do from around 50,000 years ago or so, even though the underlying reason why the ancestral artists produced art may also have increased the chances that some of them suffered from mental disorders.

A heritable trait possessed by males and perceived as very sexy by females has a very good chance of evolving in any population. That is so even if the trait causes the males who possess it to die much earlier than other males. In the human species, a male can father literally hundreds of children in just a few years. Unlike men, women tend to be very selective of their sexual partners, which does not mean that they cannot all select the same partner (Buss, 1999).

So, if this is true, what is the practical value of knowing it?

It seems reasonable to believe that knowing the likely source of a strange and unpleasant view of the world is, in and of itself, therapeutic. A real danger, it seems, is in seeing the world in a strange and unpleasant way (e.g., as a schizophrenic may see it), and not knowing that the distorted view is caused by an underlying reason. The stress coming from this lack of knowledge may compound the problem; the symptoms of mental disorders are often enhanced by stress.

As one seeks professional help, it may also be comforting to know that something that is actually very good, like creative intelligence, may come together with the bad stuff.

Finally, is it possible that our modern diets and lifestyles significantly exacerbate the problem? The answer is "yes", and this is a theme that has been explored many times before by Emily Deans. (See also this post, by Emily, on the connection between mental disorders and creativity.)

Reference(All cited references are listed in the article below. If you like mathematics, this article is for you.)

Sunday, October 9, 2011

This morning I spoke with a lady in a coffeeshop who told me she "heard on Dr. Oz" that she should be eating an egg a week for her eyes. I told her differently: she may need to eat them more often than once a week, turn to spinach, or supplement with lutein and zeaxanthin for her aging eyes. Now, because she said she'd get online and read this blog, I want to back my statements up.

In 2009, University of Massachusetts researchers (1) evaluated lutein and zeaxanthin from egg yolks on older adults with low macular pigment optical density, most whom were taking statins to lower cholesterol.* They found that eating four egg yolks per day, and possibly two egg yolks per day, improve macular health after five weeks. Notably, the treatments also increased HDL cholesterol, but not LDL cholesterol.Previous studies showed lutein and zeaxanthin from spinach, corn or supplements (2 to 30 milligram doses) can also increase macular pigment optical density. However, one study (2) showed the bioavailability of lutein was higher from lutein-enriched eggs than from spinach or supplements.

AREDS2 is a multi-center randomized trial, sponsored by the National Eye Institute, designed to evaluate high-doses of the xanthophyls and/or long-chain omega-3s (DHA and EPA) for treating AMD and cataracts. They study began in 2008 and will follow 4,000 participants for five and six years. Previously, AREDS1 showed antioxidant vitamins (500 milligrams of vitamin C; 400 International Units of vitamin E; 15 milligrams of beta-carotene) plus zinc (80 milligrams) and copper (2 milligrams) could reduce risk of developing advanced AMD by 25 percent!

What are lutein and zeaxanthin? Lutein and zeaxanthin are a pair of chemically identical, but structurally different natural yellow pigments found in plants like spinach, kale, and corn. Egg yolks also receive their characteristic yellow color from these pigments. Other well-known carotenoid pigments are beta-carotene (a pro-vitamin A carotenoid), alpha-carotene, and beta-cryptoxanthin (a pro-vitamin A carotenoid).

In the retina of the eye, lutein and zeaxanthin make up macular pigment to absorb and filter high-energy blue light, thereby protecting pigment epithelial cells beneath the macula against photo-oxidative damage. Photo-oxidative damage in the eye, specifically, is to blame for the onset of AMD, which becomes more prevalent in the U.S. as the population grows older.

AMD is the leading cause of vision loss in elderly and currently affects 30 to 50 million worldwide.

*Note: The Un. of Massachusetts study received support from the American Egg Board, the Egg Nutrition Center, and the Massachusetts Lions Research Fund Inc.

Omega-3s, specifically long-chain omega-3s DHA and EPA found naturally in fish, have overtaken the world of nutrition as one of the most exciting areas of research in the last few decades. They are now recognized as essential for cardiovascular health and guarding against heart disease; DHA for being the most abundant fat in our brains and a key nutrient for infant and brain development as well as long-term brain health in adults; and EPA because it acts to replace other fatty acids in eicosanoid pathways to reduce inflammation in joints and the body overall.

No one would have predicted these facts half a century ago. Back in the 1960s, fats were all considered evil. There was no distinction between what fat was “good” or “bad”, writes Allport. Out of this type of thinking was born the American Heart Association’s low-fat recommendation, which was a recipe for disaster in eating.As Allport puts it: “… that’s what happens when the center doesn’t hold, when the marketplace is full of such absurdities as overly sweetened breakfast cereals, such as Cocoa Puffs and Lucky Charms, being endorsed by the American Heart Association (because they have no cholesterol or saturated fat)—when the overly simplistic, low-fat mantra of the 1980s and 1990s made the Atkins craze almost inescapable. As a dieter in Texas confides, ‘Eating low-fat guarantees that I will binge on fried foods. Eating low-carb guarantees that I will binge on a bag of chips.’”

All this back-and-forth advice on nutrition has led millions of Americans to binging in and out of diets such as Atkins and terrible eating habits that include uncontrolled portion sizes, too many calories, too many high-glycemic carbs, too much trans fats and too little exercise. Wrong advice has led to epidemics in obesity, diabetes and, soon, Alzheimer’s disease.

Omega-3s removed from food

In her book, Allport seeks to highlight another aspect of what happens when ignorance in nutritional advice food processing lifts out a key nutrient from our diets. Despite what most people might think, omega-3s are not at all rare in nature and were not even rare in what people ate only half a century ago. In fact, omega-3s are the most abundant fats on the planet, making up a part of all plant cells. However, over time, omega-3s have been purposely removed from foods completely.

Why? Because omega-3s turn rancid quickly, getting them out of vegetable oils and out of processed foods increases their stability over time. Canola oil, for example, was once high in omega-3 alpha linolenic acid (ALA) and is still one of the greatest sources of omega-3s over the last few decades in the diets of Americans. However, plant biologists have been developing lower-ALA versions for years. The same thing has happened to soy oil and other oils.

To improve shelf life of processed foods, vegetable oils included in them were also often hydrogenated to improve shelf life. They still are. Hydrogenation—whether partially or fully hydrogenated oils—drastically improves stability of the oils, but completely destroyed omega-3 content. Too often enough, partially hydrogenation also introduces harmful trans fats.

At the same time, omega-3s have been removed from the diets of the animals we eat. As Allport explains it, plants accumulate oils in form of omega-3s in their leaves while concentrating the more stable omega-6s in their seeds. As the diets of animals, such as cows, switched from one that was grass-fed to one of grains, the content of omega-3s in their flesh diminished. For example, cows that ate grass were diverted to a diet of mostly corn in their animal feed. When the animals stopped receiving sufficient omega-3s in their diets, humans as consumers also had omega-3 levels in their bodies diminish.

Giving our food an extended shelf life of food and our meat plenty of flavor through the marbling effect of feeding animals corn are an understandable goal for food producers, but, unwittingly, the removal of omega-3s from our diet, not to mention the addition of high amounts of omega-6s and trans fats, have high implications on our health.

Omega-3 Discovery

In a “stroke of luck”, writes Allport, two Danish researchers, Dr. Hans Olaf Bang (now deceased) and Dr. Jørn Dyerberg, led the world back onto the path of eating heart healthy fats. Had it not been for their discoveries, we may still be avoiding omega-3s today.

The two researchers’ curiosity had been sparked by reports that the native Inuit of Greenland, or Eskimos (as they’re commonly called), had a mysteriously low incidence of heart disease in spite of a diet rich in meat and fat, or blubber.

Dr. Bang and Dr. Dyerberg knew the world was changing and that the Inuit were becoming more Westernized by the day. They had to act right away if they were ever going to find out what in the Inuit’s diet protected their health.

Once in Greenland, they collected dozens of blood samples hoping to support an educated guess that the cardioprotective factor was due to dietary polyunsaturated fats. Upon analyzing blood samples back home in Denmark, their hypothesis was confirmed.

Their original discovery was long-chain omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and their cardioprotective benefits.

Later, research in total parenteral nutrition would reveal that omega-3s should be considered an essential fatty acid, joining omega-6. Omega-6 had beforehand earned itself the name, “the King of Fats” and omega-3s would then be its "queen".Both these families of essential fatty acids, as Allport discusses, appear to compete for the same enzymes in the body.Naming omega-3s

Why are DHA, EPA and ALA all considered part of the same omega-3 family? The concept of separating both omega-3s and omega-6s into families was the brainchild of Dr. Ralph Holman.

Because chemists often use the first letters of the Greek alphabet to indicate position of chemical groups, Dr. Holman came out with the idea that “omega”, ω, the last letter of the alphabet could be used to distinguish the tails of fatty acids to put them into families.

Writes Allport, Dr. Holman’s naming convention was to help bring more attention to the relationship between these oils by avoiding their chemical names and addressing them by the end of the fatty acid chain, their tails. When metabolized in the body, the tails didn’t change and it made sense to bring more light to this fact. It also allowed the writing of the name of the oil to be shorter. For example, the chemical name of alpha-linolenic acid would simply be “18:3ω3” instead of “cis,cis,cis-9,12,15-Octadecatrienoic acid”.

Dr. Holman worried about how other researchers would react to the new terminology, but after a while he found that more and more studies began to take on the new vocabulary. Later on, Dr. Holman would find it exciting to see his “omega-3” name be adopted around the world to educate the public about the oils.

Speedy omega-3s, slow omega-6s

As all things in nature, there is a balance to be associated with fats in the wild. It appears, for example, that in most cases the speedier animals contain greater levels of omega-3s, specifically DHA, while slower animals accumulated omega-6 oils and saturated fats.

For example, slow-speed lizards and toads have more saturated fatty acids than high-speed hummingbirds, which contain plenty of DHA. In addition, large, slow animals such as elephants would have much greater omega-6 fatty acids and saturated fats than fast animals such as mice.

Omega-3s and omega-6s may also have a role in hibernation, writes Allport. It turns out, for example, that the yellow-bellied marmot’s natural diet has more omega-3s in the summer and a great deal more omega-6s in the winter. This is a relationship between leaves and nuts. But when given a diet high in linseed oil, which is high in omega-3s, the marmot doesn’t’ go into hibernation and, when given omega-6 laboratory food, they fall asleep on schedule.

Despite differences in omega-3 content in the body, Michael Crawford was the first to discover that percent content of DHA was consistent in brains throughout the animal kingdom. DHA is also found in greater concentrations in the eyes of animals.

Bringing omega-3s back into the diet

Because of a high intake of fish, the Japanese currently have a much higher amount of omega-3 fatty acids in their diet and live longer than Westerners. How can everyone be sure they are getting enough omega-3s, especially if they don't eat much fish?

Allport writes that it will take a concerted effort of education and working with food producers to put omega-3s back into the food we eat. Already, however, we are seeing a greater leaning toward offering foods higher in omega-3s.

Consumers can help to protect their health by following some steps that Allport has laid out, which include eating plenty of fruits and vegetables, consuming oils with a healthy balance of omega-3s to omega-6s, eating a wide variety of fish, eating omega-3 enriched eggs, avoiding trans fats, cutting down on saturated fats, choosing free-range meats, and using supplements.

In conclusion, Allport makes a startling, but healthy prediction—that omega-3 status will not join serum cholesterol, LDL to HDL ratio, and C-reactive protein, but replace these other indicators as a risk factor for heart disease.

Tuesday, October 4, 2011

﻿﻿What is Madness?This is the title of a new book by psychoanalyst Darian Leader, which was reviewed in the Guardian on Saturday 1st October. Whilst I haven’t yet read the book, it looks incredibly interesting and relevant to our field. The review was by Jacqueline Rose and made for interesting reading itself, particularly her discussion around the government sponsored ‘therapy of choice,’ Cognitive Behavioural Therapy (CBT).

Rose reflects the Governments No Health without Mental Health and their commitment to evidence based therapy, which allows session-by-session outcome monitoring, predominantly measured by employment rates. Secretary of State for Health, Andrew Landsley, she notes, acknowledges that unemployment is a key factor in precipitating anxiety disorders and depression. You can see where this is leading I’m sure!

Joblessness is above 2.5 million and rising as a result of government policy, and it seems that,’ the government by its own account, is provoking the problem it is trying to cure.’

The article then eloquently discusses the commodification of humans and the emptying of our unconscious mental life. It’s a great article and one that I feel would benefit from an arts/health lens, but for me the question of what madness is, perhaps lies in the Joseph Heller inspired governance of our disconnected leaders.

Start2 (Change your life with Art)Change your life with Art is an NHS service that is totally unique. Created by Start in Manchester with the support of the Strategic Health Authority and the Department of Health, it will be a collection of creative ‘courses’ with wellbeing themes, and that will encourage people to connect to the world differently, see their own strengths, be aware of their own stress triggers and have ways to handle that stress better – all through evidence based creative activities. Although it’s not launched formally until January 2011, you can get a sneak peak here and register for updates: http://www.start2.co.uk/

A Health Lottery...Did you know about the new Health Lottery? No, not government policy, or our world famous post-code lottery, this is the one that gives a massive 20p of every pound you spend towards a good cause! The rest presumably goes to Richard Desmond, the 57th richest man in the UK and owner of Express Newspapers, OK, Television X and Red Hot TV.A taste of things to come...?

Artist in Residence Opportunity LIME are seeking two artists for a short term experimental residency project. This is a ‘paired residency’ scheme whereby each artist will work with a similar hospital department but in two hospitals, one in Bolton and one in Manchester.

Monday, October 3, 2011

If you follow a paleo diet, you follow a diet that aims to be consistent with evolution. This is a theory that has undergone major changes and additions since Alfred Russel Wallace and Charles Darwin proposed it in the 1800s. Wallace proposed it first, by the way, even though Darwin’s proposal was much more elaborate and supported by evidence. Darwin acknowledged Wallace's precedence, but received most of the credit for the theory anyway.

(Alfred Russel Wallace; source: Wikipedia)

What many people who describe themselves as paleo do not seem to know is how the theory found its footing. The original Wallace-Darwin theory (a.k.a. Darwin’s theory) had some major problems, notably the idea of blending inheritance (e.g., blue eye + brown eye = somewhere in between), which led it to be largely dismissed until the early 1900s. Ironically, it was the work of a Catholic priest that provided the foundation on which the theory of evolution would find its footing, and evolve into the grand theory that it is today. We are talking about Gregor Johann Mendel.

Much of the subsequent work that led to our current understanding of evolution sought to unify the theory of genetics, pioneered by Mendel, with the basic principles proposed as part of the Wallace-Darwin theory of evolution. That is where major progress was made. The evolution thinkers below are some of the major contributors to that progress.

Ronald A. Fisher. English statistician who proposed key elements of a genetic theory of natural selection in the 1910s, 1920s and 1930s. Fisher showed that the inheritance of discrete traits (e.g., flower color) described by Gregor Mendel has the same basis as the inheritance of continuous traits (e.g., human height) described by Francis Galton. He is credited, together with John B.S. Haldane and Sewall G. Wright, with setting the foundations for the development of the field of population genetics. In population genetics the concepts and principles of the theories of evolution (e.g., inheritance and natural selection of traits) and genetics (e.g., genes and alleles) have been integrated and mathematically formalized.

John B.S. Haldane. English geneticist who, together with Ronald A. Fisher and Sewall G. Wright, is credited with setting the foundations for the development of the field of population genetics. Much of his research was conducted in the 1920s and 1930s. Particularly noteworthy is the work by Haldane through which he mathematically modeled and explained the interactions between natural selection, mutation, and migration. He is also known for what is often referred to as Haldane’s principle, which explains the direction of the evolution of many species’ traits based on the body size of the organisms of the species. Haldane’s mathematical formulations also explained the rapid spread of traits observed in some actual populations of organisms, such as the increase in frequency of dark-colored moths from 2% to 95% in a little less than 50 years as a response to the spread of industrial soot in England in the late 1800s.

Sewall G. Wright. American geneticist and statistician who, together with Ronald A. Fisher and John B.S. Haldane, is credited with setting the foundations for the development of the field of population genetics. As with Fisher and Haldane, much of his original and most influential research was conducted in the 1920s and 1930s. He is believed to have discovered the inbreeding coefficient, related to the occurrence of identical genes in different individuals, and to have pioneered methods for the calculation of gene frequencies among populations of organisms. The development of the notion of genetic drift, where some of a population’s traits result from random genetic changes instead of selection, is often associated with him. Wright is also considered to be one of pioneers of the development of the statistical method known as path analysis.

Theodosius G. Dobzhansky. Ukrainian-American geneticist and evolutionary biologist who migrated to the United States in the late 1920s, and is believed to have been one of the main architects of the modern evolutionary synthesis. Much of his original research was conducted in the 1930s and 1940s. In the 1930s he published one of the pillars of the modern synthesis, a book titled Genetics and the Origin of Species. The modern evolutionary synthesis is closely linked with the emergence of the field of population genetics, and is associated with the integration of various ideas and predictions from the fields of evolution and genetics. In spite of Dobzhansky’s devotion to religious principles, he strongly defended Darwinian evolution against modern creationism. The title of a famous essay written by him is often cited in modern debates between evolutionists and creationists regarding the teaching of evolution in high schools: Nothing in Biology Makes Sense Except in the Light of Evolution.

Ernst W. Mayr. German taxonomist and ornithologist who spent most of his life in the United States, and is believed, like Theodosius G. Dobzhansky, to have been one of the main architects of the modern evolutionary synthesis. Mayr is credited with the development in the 1940s of the most widely accepted definition of species today, that of a group of organisms that are capable of interbreeding and producing fertile offspring. At that time organisms that looked alike were generally categorized as being part of the same species. Mayr served as a faculty member at Harvard University for many years, where he also served as the director of the Museum of Comparative Zoology. He lived to the age of 100 years, and was one of the most prolific scholars ever in the field of evolutionary biology. Unlike many evolution theorists, he was very critical of the use of mathematical approaches to the understanding of evolutionary phenomena.

William D. Hamilton. English evolutionary biologist (born in Egypt) widely considered one of the greatest evolution theorists of the 20th Century. Hamilton conducted pioneering research based on the gene-centric view of evolution, also know as the “selfish gene” perspective, which is based on the notion that the unit of natural selection is the gene and not the organism that carries the gene. His research conducted in the 1960s set the foundations for using this notion to understand social behavior among animals. The notion that the unit of natural selection is the gene forms the basis of the theory of kin selection, which explains why organisms often will instinctively behave in ways that will maximize the reproductive success of relatives, sometimes to the detriment of their own reproductive success (e.g., worker ants in an ant colony).

George C. Williams. American evolutionary biologist believed to have been a co-developer in the 1960s, together with William D. Hamilton, of the gene-centric view of evolution. This view is based on the notion that the unit of natural selection is the gene, and not the organism that carries the gene or a group of organisms that happens to share the gene. Williams is also known for his pioneering work on the evolution of sex as a driver of genetic variation, without which a species would adapt more slowly in response to environmental pressures, in many cases becoming extinct. He is also known for suggesting possible uses of human evolution knowledge in the field of medicine.

Motoo Kimura. Japanese evolutionary biologist known for proposing the neutral theory of molecular evolution in the 1960s. In this theory Kimura argued that one of the main forces in evolution is genetic drift, a stochastic process that alters the frequency of genotypes in a population in a non-deterministic way. Kimura is widely known for his innovative use of a class of partial differential equations, namely diffusion equations, to calculate the effect of natural selection and genetic drift on the fixation of genotypes. He has developed widely used equations to calculate the probability of fixation of genotypes that code for certain phenotypic traits due to genetic drift and natural selection.

George R. Price. American geneticist known for refining in the 1970s the mathematical formalizations developed by Ronald A. Fisher and William D. Hamilton, and thus making significant contributions to the development of the field of population genetics. He developed the famous Price Equation, which has found widespread use in evolutionary theorizing. Price is also known for introducing, together with John Maynard Smith, the concept of evolutionary stable strategy (ESS). The EES notion itself builds on the Nash Equilibrium, named after its developer John Forbes Nash (portrayed in the popular Hollywood film A Beautiful Mind). The concept of EES explains why certain evolved traits spread and become fixed in a population.

John Maynard Smith. English evolutionary biologist and geneticist credited with several innovative applications of game theory (which is not actually a theory, but an applied branch of mathematics) in the 1970s to the understanding of biological evolution. Maynard Smith is also known for introducing, together with George R. Price, the concept of evolutionary stable strategy (EES). As noted above, the EES notion builds on the Nash Equilibrium, and explains why certain evolved traits spread and become fixed in a population. The pioneering work by John Maynard Smith has led to the emergence of a new field of research within evolutionary biology known as evolutionary game theory.

Edward O. Wilson. American evolutionary biologist and naturalist who coined the term “sociobiology” in the 1970s to refer to the systematic study of the biological foundations of social behavior of animals, including humans. Wilson was one of the first evolutionary biologists to convincingly argue that human mental mechanisms are shaped as much by our genes as they are by the environment that surrounds us, setting the stage for the emergence of the field of evolutionary psychology. Many of Wilson’s theoretical contributions in the area of sociobiology are very general, and apply not only to humans but also to other species. Wilson has been acknowledged as one of the foremost experts in the study of ants’ and other insects’ social organizations. He is also known for his efforts to preserve earth’s environment.

Amotz Zahavi. Israeli evolutionary biologist best known for his widely cited handicap principle, proposed in the 1970s, which explains the evolution of fitness signaling traits that appear to be detrimental to the reproductive fitness of an organism. Zahavi argued that traits evolved to signal the fitness status of an organism must be costly in order to the reliable. An example is the large and brightly colored trains evolved by the males of the peacock species, which signal good health to the females of the species. The male peacock’s train makes it more vulnerable to predators, and as such is a costly indicator of survival success. Traits used for this type of signaling are often referred to as Zahavian traits.

Robert L. Trivers. American evolutionary biologist and anthropologist who proposed several influential theories in the 1970s, including the theories of reciprocal altruism, parental investment, and parent-offspring conflict. Trivers is considered to be one of the most influential living evolutionary theorists, and is a very active researcher and speaker. His most recent focus is on the study of body symmetry and its relationship with various traits that are hypothesized to have been evolved in our ancestral past. Trivers’s theories often explain phenomena that are observed in nature but are not easily understood based on traditional evolutionary thinking, and in some cases appear contradictory with that thinking. Reciprocal altruism, for example, is a phenomenon that is widely observed in nature and involves one organism benefiting another not genetically related organism, without any immediate gain to the organism (e.g., vampire bats regurgitating blood to feed non-kin).

There are many other more recent contributors that could arguably be included in the list above. Much recent progress has been made in interdisciplinary fields that could be seen as new fields of research inspired in evolutionary ideas. One such field is that of evolutionary psychology, which has emerged in the 1980s. New theoretical contributions tend to take some time to be recognized though, as will be the case with ideas coming off these new fields, because new theoretical contributions are invariably somewhat flawed and/or incomplete when they are originally proposed.